Removable tooth positioning appliances (invisible braces), such as clear plastic aligners and retainers that tightly fit over teeth are commonly used in orthodontic treatments as an alternative to braces and other bonded orthodontic equipment for controlled tooth movement to a pre-determined position. These clear plastic tooth positioning appliances are not bonded to the teeth which they are used to manipulate but are made to be removed in order to eat, drink, brush, and floss the teeth as well as during dental procedures. The appliance is fabricated from a mold of the patient's teeth in order to provide accuracy of placement in compliance with the exact shape of the teeth or the exact shape and any necessary attachment devices. See U.S. Pat. No. 6,183,248 for an example of such a removable tooth positioning appliance which is incorporated herein in its entirety by reference. Total treatment time with clear plastic aligners averages 9-15 months and the average number of aligners worn during treatment is between 18 and 30, but both will vary from case to case. When teeth are moved into their final position patients are then only required to wear the aligners at night.
Removable tooth positioning appliances consist of a thin shell of clear material that conforms to a patient's teeth but just slightly out of alignment with the initial tooth configuration. By properly choosing the configuration, placement of the appliance over the teeth will move individual teeth to desired intermediate or final positions over time. These positioning appliances can be designed to fit over any number of teeth, and are typically designed to be placed over the entire top and/or bottom set of teeth.
To achieve the repositioning forces required to move a tooth from one position to another position these tooth positioning appliance must be relatively stiff (i.e. possess a high strength or high modulus) to provide a sufficient grip on the teeth. The stiffness provides the repositioning force necessary to move the teeth and ensures that the dental appliance remains firmly in position on the patient's teeth. The stiffness also permits the positioning appliance to grab hold of an anchor device or attachments on the tooth to apply a directed force to execute orthodontic tooth movements.
The stiffness of the tooth positioning appliance and the requirement that the appliance tightly conform to the teeth of the patient makes it difficult to remove these appliances. It is necessary to remove the positioning appliance many times daily in the course of the patient's daily life for cleaning, dental hygiene, to eat, and removal for cosmetic purposes and replacement in the course of treatment. Patients are instructed to use their fingers and fingernails to remove the appliances but they often find removing the appliances to be difficult and in many cases painful. Patients also find it unsanitary to be continually putting their hands in their mouths. Because removal of the appliances requires a lever action patients often will attempt to use household instruments, such as forks, spoons, or nut picks to remove their tooth positioning appliance. Using improvised instruments can damage the patient's teeth, gums and the appliance itself. During visits to the dental practitioner these practitioners use orthodontic instruments designed for other uses to remove the appliance. These orthodontic appliances often present the same problems and dangers as the patient's improvised instruments. For these reasons, it is desirable to provide a lightweight and convenient tool that is specifically designed to remove such tooth positioning appliances from a patient's teeth in a safe, easy, and effective manner.